1. Field of the Invention
The present invention relates to an image recording apparatus, in which liquid is supplied from a liquid chamber to a recording head, and to a liquid cartridge comprising the liquid chamber.
2. Description of Related Art
In a known image recording apparatus, ink is supplied to a recording head via a flow path from an ink cartridge or an ink tank storing ink therein. When the ink stored in the ink cartridge or ink tank is used up, the ink cartridge needs to be replaced or the ink tank needs to be refilled with ink. For the replacement or for the refill, there is a known technology enabling determination of a remaining amount of ink in the ink cartridge or the ink tank with an optical detector. For example, in a known image recording apparatus, as described in Patent Application Publication No. JP 5-332812 A, an ink cartridge has a wall and an optical-path plate provided in the wall. When the inner surface of the optical-path plate contacts ink, the optical-path plate allows light to pass therethrough into the ink. When the inner surface of the optical-path plate does not contact ink, light is totally reflected at the inner surface. By detecting whether or not light emitted from a light emitter is totally reflected, a remaining amount of ink in the ink cartridge is determined.
A known image recording apparatus, as described in Patent Application Publication Nos. JP 59-204567 A, 63-57238 A, 2006-231528 A, or 2005-111955 A, has a space in fluid communication with an ink chamber for storing ink. The space is at least partly defined by a membrane. When ink is consumed, the volume of the space decreases while the membrane deforms. By detecting the deformation of the membrane, a remaining amount of ink in the ink chamber is determined.
In the known image recording apparatus as described in Patent Application Publication No. JP 5-332812 A, when the optical-path plate is tainted by dried ink, the remaining amount of ink may not be accurately determined. In the known image recording apparatus as described in Patent Application Publication Nos. JP 59-204567 A, 63-57238 A, 2006-231528 A, or 2005-111955 A, the ink chamber is air-tight, i.e., is not in fluid communication with atmospheric air. When the ink chamber is air-tight, the ink chamber needs to shrink in order for ink to smoothly flow out of the ink chamber. For that reason, the ink chamber is conventionally defined by a bag (pouch), which may shrink easily. Nevertheless, there may not be a wide range of variety of materials for making the shrinkable bag. Moreover, when the ink chamber defined by the bag is positioned in a rectangular parallelepiped casing of the ink cartridge, the ink-storing capacity relative to the inner volume of the casing may not be high.